A voluntary recall of a popular step stool sold at Target is being expanded because of reports that the stool is collapsing under the weight of users and causing injury.

More than 200,000 units of Target’s “Step Stools with Storage” were recalled on Aug. 4. On Wednesday, the U.S. Consumer Product Safety Commission (CPSC) announced that an additional 341,000 units were being recalled.

Target has received 27 reports of the stools breaking or collapsing. The incidents involved 14 children, eight adults and five people of unknown age; two adults broke their wrists and one of those victims also fractured her hip and pelvis. Six children and one adult suffered scrapes and bruising.

The wooden stools have two steps and come in various colors, including natural, honey, white, pink and blue. Some models have a lid on the bottom step that lifts to provide storage; others have a lid on the top step.

All units were sold between January 2007 and October 2010 at Target stores or through Target.com, for $25 to $30 each. For specific information about the exact models in question, consumers can call Target at 800-440-0680 or see the CPSC’s recall announcement here.

Consumers are being advised to stop using the step stools immediately and return them to any Target store for a full refund.

Meredith Melnick is a reporter at TIME. Find her on Twitter at @MeredithCM. You can also continue the discussion on TIME’sFacebook page and on Twitter at @TIME.